At National Journal’s Transportation Expert’s blog Lisa Caruso writes, “Last week the country marked the eighth anniversary of the Sept. 11 terrorist attacks, when terrorists hijacked commercial airliners and flew them into the World Trade Center, the Pentagon and, in the only thwarted attempt, a field in western Pennsylvania. The attacks exposed glaring vulnerabilities in our transportation security system and made addressing security threats to all modes of transportation a top priority for government and the private sector alike. Eight years later, where do we stand on that effort? Where has transportation security been enhanced and where do gaps still exist? What do we need to do next?”

Eight years ago, Congress enacted the Aviation & Transportation Security Act (ATSA) of 2001 in great haste, with very little prior study or research. The overwhelming political need was to reassure the voting public that something was being done to prevent a repeat of the horrible commandeering of airliners as weapons of mass destruction on 9/11. Consequently, despite having the words “transportation security” in its title, ATSA devoted the vast majority of its mandates and funding to commercial aviation security. That not only leaves gaping vulnerabilities in other transportation modes but also focuses far too much aviation security resources on keeping dangerous objects off airliners rather than making all of aviation less vulnerable.

A major problem inherent in dealing with security against terrorism via political means is the tendency to focus what are always scarce resources on highly visible efforts—what some have termed “security theater.” The alternative is to base security policy on serious risk analysis, putting resources where they achieve the greatest bang for the buck. That kind of analysis in aviation security suggests that spending $4 billion per year on screening every passenger and bag (rather than focusing resources more on higher-risk passengers) and stationing air marshals on airliners are not cost-effective uses of security dollars. If we spent less of these resources on security theater and more on preventing airfield perimeters from being breached and lobbies from being targeted by suicide bombers, we’d likely be better off. And by the same token, serious risk analysis might suggest spending relatively less on aviation security and relatively more on rail and cargo security.

Ultimately, countering domestic terror threats via a strategy of target-hardening is a losing proposition. A wealthy free society is inherently a target-rich environment—and we cannot afford to spend a sizeable fraction of our GDP hardening every possible target. The more we focus large sums on building a few hardened “Maginot Lines,” the more terrorists can shift to less-hardened or un-hardened targets—whether fuel storage facilities, long-distance power lines, or shopping malls. This suggests that a significant fraction of whatever we can afford to spend should be spent on intelligence work and counter-terrorist efforts rather than target-hardening.